S60 AC blowing warm air

The symptoms you describe suggest a potential issue within the air conditioning system itself. Has the system’s pressure been checked? Are you noticing any unusual noises when the AC is engaged, even if it isn’t cooling? These details can help narrow down the possibilities.

Thanks for the quick reply! No unusual noises, and I haven't had the system pressure checked (don't have the tools). Could it be something like a faulty pressure switch, or maybe even the AC relay?

While a pressure switch or relay issue is possible, the complete failure to engage suggests a broader problem. Given the age of your vehicle and the mileage, a defect affecting the valves within the AC system itself is a strong possibility. Unfortunately, specialized diagnostic equipment will be required to pinpoint the exact faulty component. I recommend consulting a qualified technician.

Appreciate the diagnosis! I took it to a shop and turns out you were spot on. They confirmed a faulty valve issue, and the repair cost 1000€. Not ideal, but at least I know what the problem was. Thanks again!